Joshua 8:3

3 And Joshua rose, and all the host of fighting men with him, for to go up into Ai; and by night he sent (away) thirty chosen thousand of strong men; (And so Joshua, and all his army of fighters, rose up to go into Ai; and he chose thirty thousand strong men, and sent them away in the night;)

Joshua 8:3 Meaning and Commentary

Joshua 8:3

So Joshua arose, and all the people of war, to go up against
Ai
As the Lord had commanded him:

and Joshua chose out thirty thousand mighty men of valour;
out of all the men of war; these were a select company, picked men, not the whole army, as some have thought, for he was ordered to take all the people of war, as he did:

and sent them away by night;
from the main army, that they might pass the city and get behind it undiscovered, for they were sent for an ambush; and of these some were to take the city, and be left in it to burn it, and some to smite the men of Ai, as Abarbinel notes.

Joshua 8:3 In-Context

1 And the Lord said to Joshua, Neither dread thou, nor be thou afeared; take with thee all the multitude of fighting men, and rise thou, and go up into the city of Ai; lo, I have betaken into thine hand the king thereof, and the people, and the city, and the land.

2 And thou shalt do to the city of Ai, and to the king thereof, as thou didest to Jericho, and the king thereof; soothly ye shall take to you the prey (but this time ye can take the prey for yourselves), and all [the] living beasts; (and this time,) set thou ambushes, either ambushments, to the city behind it.

3 And Joshua rose, and all the host of fighting men with him, for to go up into Ai; and by night he sent (away) thirty chosen thousand of strong men; (And so Joshua, and all his army of fighters, rose up to go into Ai; and he chose thirty thousand strong men, and sent them away in the night;)

4 and he commanded to them, and said, Set ye ambushments behind the city, and go ye not further; and all ye shall be ready (and all of ye be ready to fight);

5 forsooth I, and the tother multitude which is with me, shall come on the contrary side against the city; and when they shall go out against us, as we did before, we shall flee, and turn the backs, (and I, and the other multitude who be with me, shall come on the opposite side toward the city; and when they shall go out against us, we shall turn our backs, and flee, as we did before,)